Colicins as antibiotic alternatives for the treatment and prevention of post-weaning diarrhea and edema disease in swine

It is estimated that over 50% of all economic losses in weaned pigs are due to Escherichia coli infections, causing either diarrhea or edema disease. Despite animal health and economic concerns, concerns over the spread of antibiotic resistance will limit the types of antibiotics that can be used in production animals. Therefore, we have examined alternatives to conventional antibiotics

Dietary Inclusion of Colicin E1 Prevents Post-weaning Diarrhea in Pigs

Including a purified antimicrobial peptide, Colicin E1, at a rate of 22mg/kg diet in a corn-soy based diet for weanling pigs prevented experimentally induced (E. coli F18) post-weaning diarrhea. Colicins may be an effective alternative to conventional antibiotics for use in animal feed

Dietary Inclusion of Colicin E.: Effect on Pig Behavior

In the US prophylactic antibiotics are frequently included in the diets of weanling pigs to prevent postweaning diarrhea (PWD). Despite this, PWD still causes substantial losses to the swine industry through both mortalities and morbidly. Additionally, the use of prophylactic antibiotics has become a concern among some groups regarding their potential contribution to the spread and creation of antibiotic resistant bacteria. The objective of this study was to determine if dietary inclusion of Colicin E1 (ColE1) altered a pigs behavior and postures when challenged with E. coli. Twenty-four newly weaned barrows; 21 days of age were placed into individual pens. Three dietary treatments were compared; treatment 1 had no ColE1 (C; n=8), treatment 2 added 1.1 mg of purified ColE1 (L; n=8), and treatment 3 added 16.5 mg (H; n=8) of purified ColE1. Two behaviors were collected; time spent at the feeder trough and drinking. Three postures were collected; active and inactive and other. There were no (P \u3c 0.05) effects on the time engaged in active, drinking and other. For pigs in the H group they engaged in more (P \u3c 0.05) eating and less time in inactive postures than C pigs. From this study, it can be concluded that pigs with the highest coverage of ColE1 displayed less inactive behaviors and spent more time at the feeder indicating that ColE1 may have offered some form of protection against the E. coli challenge and therefore improved the individual pig’s wellbeing

Dietary Inclusion of Colicin E1.: Effect on Behavior Over Time

In the U.S., prophylactic antibiotics are frequently included in the diets of weanling pigs to prevent postweaning diarrhea (PWD). Despite this, PWD still causes substantial losses to the swine industry through both mortalities and morbidity. Additionally, the use of prophylactic antibiotics has become a concern among some groups regarding their potential contribution to the spread and creation of antibiotic resistant bacteria. The objective of this study was to determine if dietary inclusion of Colicin E1 (ColE1) altered pigs behavior and postures when challenged with E. coli over a 24 h period. Two postures (active and inactive) and two behaviors (drinking and feeding) were compared over three dietary treatments; treatment 1 had no ColE1 (C; n=8), treatment 2 added 1.1 mg of purified ColE1 (L; n=8), and treatment 3 added 16.5 mg (H; n=8) of purified ColE1. Regardless of treatment, nursery aged pigs generally engaged in higher levels of active postures, drinking behaviors, and feeding behaviors during the afternoon and night (13:00 to 22:00). Inversely, the pigs were generally inactive during the late night and morning hours (22:00 to 13:00). Nursery pigs in the H groups displayed slightly higher levels of active postures and feeding behaviors over a 24 h period indicating that ColE1 had some positive effects on the well-being of pigs infected with E. coli

Human-Robot Teaming Configurations: A Study of Interpersonal Communication Perceptions and Affective Learning in Higher Education

Technology encourages collaboration in creative ways in the classroom. Specifically, social robots may offer new opportunities for greater innovation in teaching. In this study, we combined the established literature on co-teaching teams with the developing field of machine actors used in education to investigate the impressions students had of different team configurations that included both a human and a robot. Participants saw one of three teams composed of a human and a social robot with different responsibilities present a short, prerecorded lecture (i.e., human as lead teacher-robot as teaching assistant, robot as lead teacher-human as teaching assistant, human and robot as co-teachers). Overall, students rated the human-led team as more appealing and having more credibility than the robot-led team. The data suggest that participants would be more likely to take a course led by a human instructor than a social robot. Previous studies have investigated machine actors in the classroom, but the current findings are unique in that they compare the individual roles and power structures of human-robot teams leading a course

Genetic Pathways to Environmentally Friendly Pigs

The Environmental Protection Agency (EPA) has enacted regulations that will restrict the amount of phosphorus (P) that can be applied to land. With the vast majority of swine production sites operating at high stocking densities and having less available land on which to apply animal effluent, increased P levels in manure could substantially increase production costs

A calcitonin receptor (CALCR) single nucleotide polymorphism is associated with growth performance and bone integrity in response to dietary phosphorus deficiency

Although concerns over the environmental impact of excess P in the excreta from pig production and governmental regulations have driven research toward reducing dietary supplementation of P to swine diets for over a decade, recent dramatic increases in feed costs have further motivated researchers to identify means to further reduce dietary P supplementation. We have demonstrated that genetic background impacts P utilization in young pigs and have identified genetic polymorphisms in several target genes related to mineral utilization. In this study, we examined the impact of a SNP in the calcitonin receptor gene (CALCR) on P utilization in growing pigs. In Exp. 1, 36 gilts representing the 3 genotypes identified by this CALCR SNP (11, 12, and 22) were fed a P-adequate (PA) or a marginally P-deficient (approximately 20% less available P; PD) diet for 14 wk. As expected, P deficiency reduced plasma P concentration, bone strength, and mineral content (P \u3c 0.05). However, the dietary P deficiency was mild enough to not affect the growth performance of these pigs. A genotype × dietary P interaction (P \u3c 0.05) was observed in measures of bone integrity and mineral content, with the greatest reduction in bone strength and mineral content due to dietary P deficiency being associated with the allele 1. In Exp. 2, 168 pigs from a control line and low residual feed intake (RFI) line were genotyped for the CALCR SNP and fed a PA diet. As expected, pigs from the low RFI line consumed less feed but also gained less BW when compared with the control line (P \u3c 0.05). Although ADFI did not differ between genotypes, pigs having the 11 genotype gained less BW (P \u3c 0.05) than pigs having the 12 or 22 genotypes. Pigs of the 11 and 12 genotypes had bones that tolerated greater load when compared with animals having the 22 genotype (P \u3c 0.05). A similar trend was observed in bone modulus and ash % (P \u3c 0.10). These data are supportive of the association of this CALCR SNP with bone integrity and its response to dietary P restriction. Although the allele 1 is associated with greater bone integrity and mineral content during adequate P nutrition, it is also associated with the greatest loss in bone integrity and mineral content in response to dietary P restriction. Understanding the underlying genetic mechanisms that regulate P utilization may lead to novel strategies to produce more environmentally friendly pigs

Response to dietary phosphorus deficiency is affected by genetic background in growing pigs

Concern over the environmental effect of P excretion from pig production has led to reduced dietary P supplementation. To examine how genetics influence P utilization, 94 gilts sired by 2 genetic lines (PIC337 and PIC280) were housed individually and fed either a P-adequate diet (PA) or a 20% P-deficient diet (PD) for 14 wk. Initially and monthly, blood samples were collected and BW recorded after an overnight fast. Growth performance and plasma indicators of P status were determined monthly. At the end of the trial, carcass traits, meat quality, bone strength, and ash percentage were determined. Pigs fed the PD diet had decreased (P \u3c 0.05) plasma P concentrations and poorer G:F (P \u3c 0.05) over the length of the trial. After 4 wk on trial, pigs fed the PD diet had increased (P \u3c 0.05) plasma 1,25(OH)2D3 and decreased (P \u3c 0.05) plasma parathyroid hormone compared with those fed the PA diet. At the end of the trial, pigs fed the PD diet had decreased (P \u3c 0.05) BW, HCW, and percentage fat-free lean and tended to have decreased LM area (P = 0.06) and marbling (P= 0.09) and greater (P = 0.12) 10th-rib backfat than pigs fed the PA diet. Additionally, animals fed the PD diet had weaker bones and also decreased (P \u3c 0.05) ash percentage and increased (P \u3c 0.05) concentrations of 1α-hydroxylase and parathyroid hormone receptor mRNA in kidney tissue. Regardless of dietary treatment, PIC337-sired pigs consumed more feed and gained more BW than their PIC280-sired counterparts (P \u3c 0.05) during the study. The PIC337-sired pigs also had greater (P \u3c 0.05) HCW, larger (P \u3c 0.01) LM area, and tended to have (P = 0.07) greater dressing percentage. Meat from the PIC337-sired pigs also tended to have greater (P = 0.12) concentrations of lactate but decreased (P = 0.07) concentrations of total glucose units 24 h postslaughter. Although plasma 1,25(OH)2D3 concentrations were elevated (P \u3c 0.05) in all the animals fed the PD diet, this elevation due to P deficiency tended (P = 0.09) to be greater in the PIC337-sired pigs after 12 wk on the treatment. The PIC337-sired pigs had stronger (P \u3c 0.01) bones with greater ash percentage than the PIC280-sired pigs. The difference in the strength of the radii between the PIC337-sired pigs fed the PA and PD diets was greater than their PIC280-sired counterparts, which resulted in sire line × treatment interactions (P \u3c 0.05). These data indicate differing mechanisms of P utilization between these genetic lines. Elucidating these mechanisms may lead to strategies to increase efficiency of growth in a more environmentally friendly manner

Occurrence of Salmonella-Specific Bacteriophages in Swine Feces Collected from Commercial Farms

Salmonella is one of the leading causes of human foodborne illness and is associated with swine production. Bacteriophages are naturally occurring viruses that prey on bacteria and have been suggested as a potential intervention strategy to reduce Salmonella levels in food animals on the farm and in the lairage period. If phages are to be used to improve food safety, then we must understand the incidence and natural ecology of both phages and their hosts in the intestinal environment. This study investigates the incidence of phages that are active against Salmonella spp. in the feces of commercial finishing swine. Fecal samples (n = 60) were collected from each of 10 commercial swine finishing operations. Samples were collected from 10 randomly selected pens throughout each operation; a total of 600 fecal samples were collected. Salmonella spp. were found in 7.3% (44/600) of the fecal samples. Bacteriophages were isolated from fecal samples through two parallel methods: (1) initial enrichment in Salmonella Typhimurium; (2) initial enrichment in Escherichia coli B (an indicator strain), followed by direct spot testing against Salmonella Typhimurium. Bacteriophages active against Salmonella Typhimurium were isolated from 1% (6/600) of the individual fecal samples when initially enriched in Salmonella Typhimurium, but E. coli B-killing phages were isolated from 48.3% (290/600) of the fecal samples and only two of these phages infected Salmonella Typhimurium on secondary plating. Collectively, our results indicate that bacteriophages are widespread in commercial swine, but those capable of killing Salmonella Typhimurium may be present at relatively low population levels. These results indicate that phages (predator) populations may vary along with Salmonella (prey) populations; and that phages could potentially be used as a food safety pathogen reduction strategy in swine